==CORRECTIONS==
Sang Hyup: I will invent a teleport device that helps people to travel long distances at a moment.
Correct: I will invent a teleporting device that helps people to travel long distances at a moment.
Explanation: In using the (-ing form) it emphasizes that the word "Teleport" as a noun and not and adjective in the sentence because it is what is being talked about or the subject in the sentence.

Sang Hyup: People nowadays live a busy and hectic life and they usually spend a lot of time on roads since the more cities has developed, the worse the traffic ham is.
Correct: People nowadays live in a busy and hectic life and they usually spend a lot of time on roads since more cities has developed and what is much worse example is a traffic jam.
Explanation: Sometimes we tend to jumble some words in our sentence, so in order for our idea to be accurate check the word relations to each other and makes your sentences simpe as possible.

                                        ===NOTES===
Hello Sang Hyup! A job well done on expresing your thoughts about this theme for your homework. I also do agree on your idea that saving time also improves the quality of life just like submitting your homework in time! Just take note of the corrections for this homework and as far as you study I can see that you're really doing well. Keep up the good work. I'll see you tomorrow. Bye :)

~Teacher Carrie